Every section banner dies (103 -> 0) across test/lang, the observer
suites, the C carriers, and the five comment-heavy corpus fixtures;
banner provenance (#N cites, carrier numbers, repair-cluster labels)
folded into headers or adjacent WHY comments. Narration deleted; row
provenance, ref cites, divergence pins, and layout contracts kept
(fwd-ref decl-order guards and bootstrap-gate corpus rationale
restored where the sweep over-cut). Comment-only proven: all 3742
wwbuild workdir .s byte-identical before/after; test-commit and
test-byteid (161 lang + 1399 data, 0 pinned-divergent) green.
`let s: str = *h` (a str/slice loaded by value through *str / *[]T)
fell through the N_UN deref arm to the scalar load, emitting a single
MOVQ that read only the 8B .ptr and left .len/.cap from stale registers,
so len(*p) returned garbage. Both stages emitted byte-identical wrong
code, so the self-compile byte-id gate was blind to it. Add a str/slice
arm that loads the full {ptr,len,cap} via cgslicehdr when the chased
pointee is TY_STR/TY_SLICE.
Surfaced by the codegen miscompile hunt (finding C1b). Pinned by
test/lang/deref_hdr_test.ww, which interposes a different-sized decoy
header so the test reddens when the arm is reverted.
